This invention relates to recording and/or reproducing data. The present invention especially relates to recording and/or reproducing data which emphasizes the continuity in time of a reproducing operation for rewrittable recording medium.
For the rewrittable recording medium, it is popular to develop the method for recording and/or reproducing the data which emphasizes the continuity in times such as for image, voice, etc.
Generally, the seek operation to a desired address is slow in an optical disk medium like DVD-RAM, DVD-RW, etc., since the inertia of the movable parts, such as the optical pickup, is big. In the ZCLV (Zoned Constant Linear Velocity) system for using at DVD-RAM, the overhead is increased, and then the data access speed is comparatively slow, since the rotational frequency of the medium must be changed in every zone.
FIGS. 1A and 1B show a recording and/or reproducing method to be generally used in order to reproduce the data continuously in time by using the recording medium in which the data access speed is comparatively slow, wherein analysis is a part of the present invention.
At first, as shown in FIG. 1A, the data, which is read out through reproducing system 2 from the recording medium 1, is stored in buffer 3 at data readout speed Vr. In the meantime, when the data is read out from buffer 3, it is output at data reproducing speed Vo to a decoder 4.
As shown in FIG. 1B, in the time of Tr, during which data was read out from the recording medium, the data volume in the buffer increases at the speed of (Vrxe2x88x92Vo), and in the time of Tj when data can not be read out because of the jump (the seek+data volume in the buffer decreases at the speed of (xe2x88x92Vo). From the standard data speeds of Vr, Vo, and the worst jump time of Tj, the readout time of Tr needed to assure that the buffer does not empty during jump time, can be calculated from (Vrxe2x88x92Vo)Trxe2x88x92Voxc2x7Tj greater than 0 with Tr greater than Tjxc2x7Vo/(Vrxe2x88x92Vo). It has been proven that the data volume over (Vrxc2x7Tr) must be written beforehand in contiguous addresses in order to reproduce the data continuously at the speed of Vr during the time of Tr. For example, when it is assumed Vr=11 Mbps, Vo=largest 8 Mbps, and Tj=1 second, Vrxc2x7Tr=11xc2x71xc2x78/(11xe2x88x928)=29.3 Mbit=3.7 MB and then the data volume over this amount must be written contiguously.
There was a problem to generate data fragmentation and not satisfy the regulation quantity (Vrxc2x7Tr) in the case when the data was copied in other recording medium, even if the data over the regulation quantity (Vrxc2x7Tr) was recorded beforehand and contiguously on the recording medium. This problem is explained by using FIGS. 2A and 2B.
To begin with, it is assumed that the data (5-1) having a quantity over the regulation quantity (Vrxc2x7Tr) is recorded contiguously in a recording operation as shown in FIG. 2A. When the data is copied on the recording medium of FIG. 2B and other data (6-1, 6-2) has already used a part of the area, it is usual to record data (5-2, 5-3, 5-4) by avoiding the area of data 6-1, 6-2. This time, the length of the unit (extent) in which the data is recorded contiguously becomes decreased shorter than the aforesaid regulation quantity, and the data occupancy in the buffer shown at FIG. 1B became zero, when jump occurred over the areas (6-1, 6-2) and a reproducing operation became discontinuous in time.
Therefore, the object of this invention is to provide a method for recording and/or reproducing data which does not produce the above discontinuous reproducing failure, even if the data on the recording medium is copied in other recording medium, in the system which emphasizes the continuity in time of the reproducing operation.
Whether the data on the recording medium is able to reproduce continuously in time before reproducing or not is judged in order to achieve the aforesaid object, and the data is rearranged contiguously from the point of physical data allocation in the case of a judgement of not being able. The configuration in which the data is recorded physically contiguously is shown according to a flag, and the presence of the flag presents the data fragmentation being generated in the copy.
Or, the data is provided with a copy prohibition attribution in order to forbid copying itself.
Or, the data is read out, and the prohibition attribution is chosen.
Or, when judged whether the data was copied or not and then it was copied, the reproducing is stopped.
Or, the data is reproduced after it is rearranged, so that the data may be allocated physically contiguously from the point of physical data allocation.